I am working off of memory here, but I think the 1998 earthquake was associated with significant seafloor displacement, possibly an undersea landslide. This quake has a hypocentral depth of 33+/- kilometers, or roughly 18 to 20 miles deep (I am unsure of the water depth in the trench area). So the opportunity for significant seafloor displacement due to fault rupture is minimal.
The seimic shaking, in and of itself, is not likely to cause a large tsunami.